you problably warped the pan by overtightening it. i did that to mine, and bent the top lip that the gasket seals on. ordered new pan, and it used much much stronger metal that would be impossible to bend and break.

or

you are overfilling your tranny. the pan can only hold about 5 liters, so if you are tyring to fill it up all the way by just pouring it in, after about 5 liters it will come out of the vent above the pan. put in 4 liters, then start engine and without moving go through the gears slowly, stopping in each position. then fill up to full.
dont forget to heat the tranny up to temp before getting the correct about in.

will it hurt the tranny to have it overfilled? say 1/2 inch above the mark?

__________________

Grey '91 350SDL 214k Dad's car FOR SALE!!
Beige '81 240D 4 Speed 254k SOLD
Blue '82 300D 225k SOLD
White '95 E300D 46k SOLD
Blue '87 190D 2.5 Turbo 315k SOLD
Brown '80 240D 4 Speed 716k SOLD
Beige '80 300D N/A 119k SOLD
Blue '85 300D Model 186k T-Boned